(1、中南工業(yè)大學(xué)粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室、礦物工程系， 長(zhǎng)沙 410083
2、中國(guó)有色金屬工業(yè)總公司，北京 100814)
摘 要: 通過(guò)對(duì)高嶺石和鋁土礦焙燒過(guò)程物相變化的X射線衍射研究，闡明了鋁土礦化學(xué)選礦預(yù)脫硅的機(jī)理。實(shí)驗(yàn)表明，礦石中固有的α-SiO2(石英)是不能被脫除的， 只有在焙燒溫度高達(dá)900 ℃以上、 由偏高嶺石分解形成的那部分非晶SiO2才 能被NaOH溶出而脫除。此外，溶出精礦的相分析結(jié)果澄清了過(guò)去認(rèn)為在低壓溶出脫硅條件下高嶺土是穩(wěn)定存在的誤解。給出了提高鋁土礦鋁硅比值的最佳焙燒工藝制度。
關(guān)鍵字: 鋁土礦 高嶺石 脫硅 焙燒 X射線衍射
（1.P/M National Key Laboratory, Central South University of Technology, Changsha 410083 ;
2.China National Nonferrous Metals Industry Corporation, Beijing 100814）
Abstract:The phase transitions of kaolinite and diasporic bauxite during roasting were studied by means of XRD analysis. The desilication mechanism of diasporic bauxite by chemical processing was explained. It was shown that the α-SiO2(quartz) in green ores can not be separated, but the amorphous SiO2 formed by roasting kaolinite at temperature above 900 ℃ can be desilicated. The XRD analysis results of digested products cleared the misunderstanding that the kaolinite was the stable phase under the low pressure digestion condition. The suitable roast rule to increase the Aluminum/Silicon ratio(A/S) of diasporic bauxite was also presented.
Key words: diasporic bauxite kaolinite desilication roast XRD
